fix(shell): clean up rcfiles and remove redundancies

- Remove deprecated GREP_OPTIONS (handled via alias)
- Quote $ZSH_COMPDUMP to prevent word splitting
- Remove duplicate vim alias (nvim alias takes precedence)
- Consolidate completion path to ZSH_CUSTOM_COMPLETION_PATH
- Simplify PATH setup in rcfiles, centralize in exports
- Move LM Studio PATH from rcfiles to exports
- Add clarifying comments for macOS-specific ssh-add

config/alias

@@ -7,8 +7,6 @@ x-have eza && {
   alias ls="eza -h -s=type --git --icons --group-directories-first"
 }
 
-alias vim='vim -u "$XDG_CONFIG_HOME/vim/vimrc"'
-
 # Easier navigation: .., ..., ....
 alias ..="cd .."
 alias ...="cd ../.."